Variability in the phenotypic expression of fryns syndrome: A report of two sibships

Diaphragmatic Hernia as a Prenatal Feature of Glycosylphosphatidylinositol Biosynthesis Defects and the Overlap With Fryns Syndrome - Literature Review

Fryns syndrome is an autosomal recessive multiple congenital anomaly syndrome, with diaphragmatic defects and secondary lung hypoplasia as cardinal features. Despite it was reported first in 1979, its exact etiology has not been established to date. With this review, we would like to draw attention to the prenatal presentation of multiple congenital anomalies syndromes, resulting from defects in the synthesis of glycosylphosphatidylinositol anchors, to be considered in a prenatal assessment of fetuses with DH and Fryns-like phenotype.

A system-based approach to the genetic etiologies of non-immune hydrops fetalis

A wide spectrum of genetic causes may lead to nonimmune hydrops fetalis (NIHF), and a thorough phenotypic and genetic evaluation are essential to determine the underlying etiology, optimally manage these pregnancies, and inform discussions about anticipated prognosis. In this review, we outline the known genetic etiologies of NIHF by fetal organ system affected, and provide a systematic approach to the evaluation of NIHF. Some of the underlying genetic disorders are associated with characteristic phenotypic features that may be seen on prenatal ultrasound, such as hepatomegaly with lysosomal storage disorders, hyperechoic kidneys with congenital nephrosis, or pulmonary valve stenosis with RASopathies. However, this is not always the case, and the approach to evaluation must include prenatal ultrasound findings as well as genetic testing and many other factors. Genetic testing that has been utilized for NIHF ranges from standard chromosomal microarray or karyotype to gene panels and broad approaches such as whole exome sequencing. Family and obstetric history, as well as pathology examination, can yield additional clues that are helpful in establishing a diagnosis. A systematic approach to evaluation can guide a more targeted approach to genetic evaluation, diagnosis, and management of NIHF.

Fryns syndrome: a lethal birth defect with variable phenotypic expressions in siblings

Fryns syndrome (FS) is a multiple congenital anomaly syndrome, inherited as an autosomal recessive defect with variable expression. The authors report a newborn with FS, whose mother had two previous affected pregnancies with the infants having variable phenotypic expression. FS is characterized by craniofacial dysmorphism, diaphragmatic hernia and distal limb hypoplasia. This is the first published report from India describing a case of FS with familial recurrence, which would serve further to illustrate the clinical variability of this disorder.

Exome sequencing identifies a recessive PIGN splice site mutation as a cause of syndromic congenital diaphragmatic hernia

Using exome sequencing we identify a homozygous splice site mutation in the PIGN gene in a foetus with multiple congenital anomalies including bilateral diaphragmatic hernia, cardiovascular anomalies, segmental renal dysplasia, facial dysmorphism, cleft palate, and oligodactyly. This finding expands the phenotypic spectrum associated with homozygous loss of function mutations in PIGN, and adds further support for defective GPI anchor biosynthesis as a cause of developmental abnormalities. We demonstrate that exome sequencing is a valuable approach for the identification of a genetic cause in sporadic cases of multiple congenital anomalies (MCA) due to inherited mutations.

Fryns syndrome without diaphragmatic hernia, DOOR syndrome or Fryns-like syndrome? Report on patients from Indian Ocean islands

We report on six patients (five unpublished patients) from the Indian Ocean islands, with coarse face, cleft lip or palate, eye anomalies, brachytelephalangy, nail hypoplasia, various malformations (genitourinary or cerebral), abnormal electroencephalograms with impaired neurological examination and lethal outcome. Massive polyhydramnios was noted in the third trimester of pregnancy and neonatal growth was normal or excessive. The combination of the features is consistent with the diagnosis of Fryns syndrome (FS) without congenital diaphragmatic hernia. Besides chromosomal aberrations and microdeletion syndrome, differential diagnoses include conditions overlapping with FS such as Simpson-Golabi-Behmel, and conditions with hypoplasia/absence of the distal phalanges such as DOOR syndrome, Schinzel-Giedion syndrome, and Rudiger syndrome.

Sporadic familial ulnar hexadactyly of all four limbs

BACKGROUND

Polydactyly belongs to skeletal anomalies and may be a symptom of more complex genetic syndromes.

MAIN OBSERVATION

We observed an index case of ulnar hexadactyly of all four limbs in a 20-year-old man from India with three more brothers affected in his family. No additional anomalies were observed. The diagnosis of a sporadic (ulnar) postaxial hexadactyly was made.

CONCLUSION

Sporadic postaxial hexadactyly is one of the most common polydactylies in humans. In contrast, in the dermatologic literature the condition has only rarely been described.

CONCLUSION

Presence of supernummary digits or toes, i.e. polydactyly, is seen occasionally in the dermatologic practise. The present case is extraordinary since all limbs were involved and the same was true for three of his brothers. If treatment is asked, hand surgery would be necessary.

Syndrome de Fryns. Présentation de 3 nouvelles observations

BACKGROUND

Fryns syndrome is a lethal autosomal recessive syndrome which includes congenital diaphragmatic hernia (CDH), pulmonary hypoplasia, cranio-facial manifestations including a coarse face, a cleft palate / lip and cloudy corneae, distal limb hypoplasia and internal malformations including central nervous system, cardiovascular, gastrointestinal, urogenital and skeletal anomalies.

CASES REPORT

We report on 3 patients with Fryns syndrome in the french Indian Ocean islands (La Réunion and Mayotte islands). Pregnancies were complicated by polyhydramnios. All patients had coarse face, cloudy corneae, cleft lip / palate or high-arched palate, hypoplastic nails and brachytelephalangy. They died in the neonatal period. Two had CDH and 1 did not have a diaphragmatic involvement but a severe respiratory distress syndrome with refractory hypoxemia. Cytogenetic studies of blood lymphocytes and skin fibroblasts were normal.

CONCLUSIONS

Fryns syndrome is the most common multiple congenital anomaly associated with CDH. The diagnosis is strongly suggested when CHD and brachytelephalangy are associated. Phenotypes with CDH similar to Fryns syndrome have been described with cytogenetic aberrations with G-banded chromosome analysis and submicroscopic chromosome deletions detected by high resolution karyotyping or array comparative genomic hybridization (CGH). Exclusion of chromosome aberrations (including isochromosome 12p in skin fibroblasts) is needed prior to making the diagnosis of Fryns syndrome. In sporadic cases, high resolution karyotyping or array CGH should be performed for correct diagnosis and genetic counselling.

Genetic factors in congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is a relatively common birth defect associated with high mortality and morbidity. Although the exact etiology of most cases of CDH remains unknown, there is a growing body of evidence that genetic factors play an important role in the development of CDH. In this review, we examine key findings that are likely to form the basis for future research in this field. Specific topics include a short overview of normal and abnormal diaphragm development, a discussion of syndromic forms of CDH, a detailed review of chromosomal regions recurrently altered in CDH, a description of the retinoid hypothesis of CDH, and evidence of the roles of specific genes in the development of CDH.

Cardiovascular malformations in Fryns syndrome: is there a pathogenic role for neural crest cells?

We performed a comprehensive literature and case report review to characterize the cardiovascular malformations (CVMs) associated with Fryns syndrome (OMIM #229850), a multiple congenital anomaly/mental retardation syndrome consisting of diaphragmatic defects, significant pulmonary hypoplasia, distinctive facial appearance, distal digital hypoplasia, and numerous other external and internal anomalies. A total of 112 patients meeting diagnostic guidelines for Fryns syndrome were identified, of whom 82 met narrowly defined criteria (Group I) and 30 met broader diagnostic criteria (Group II). Twelve patients reported as having Fryns syndrome with atypical features (Group III) were also analyzed. A CVM was reported in 51% (42 of 82) of Group I patients, most commonly an atrial or ventricular septal defect (VSD) (23 of 42, 55%). Conotruncal and aortic arch CVMs were common (11 of 42, 26%), but not significantly so compared to the general population of infants to age 1 year [Ferencz et al., 1997]. Recognizing that minor septal defects associated with congenital diaphragmatic hernia (CDH) may occur in response to altered hemodynamics (instead of being a bonafide CVM), we excluded four patients reported as having hemodynamically insignificant VSDs. Following these exclusions, conotruncal CVMs were found more commonly than in the general population (11 of 38, 29%, P < or = 0.025). In Group II, 9 of 30 (30%) had a CVM with no predominant type among the small number of cases reviewed. Among the atypical Fryns syndrome patients in Group III, half (6 of 12, 50%) had a CVM; most (4 of 6, 67%) were conotruncal, in particular, type B interrupted aortic arch (3 of 4). Patients with Fryns syndrome have a high rate of CVMs, warranting thorough cardiac evaluation including echocardiogram (fetal and/or postnatal) in all patients, similar to the evaluation for other patients with diaphragmatic hernia. The possible association between conotruncal CVMs and Fryns syndrome may provide additional support for an etiologic role of genes related to neural crest cell development in the pathogenesis of Fryns syndrome and hence, congenital diaphragmatic hernia.

Findings from aCGH in patients with congenital diaphragmatic hernia (CDH): a possible locus for Fryns syndrome

Congenital diaphragmatic hernia (CDH) is a common and often devastating birth defect that can occur in isolation or as part of a malformation complex. Considerable progress is being made in the identification of genetic causes of CDH. We applied array-based comparative genomic hybridization (aCGH) of approximately 1Mb resolution to 29 CDH patients with prior normal karyotypes who had been recruited into our multi-site study. One patient, clinically diagnosed with Fryns syndrome, demonstrated a de novo 5Mb deletion at chromosome region 1q41-q42.12 that was confirmed by FISH. Given prior reports of CDH in association with cytogenetic abnormalities in this region, we propose that this represents a locus for Fryns syndrome, a Fryns syndrome phenocopy, or CDH.

Fryns syndrome with Hirschsprung disease: Support for possible neural crest involvement

Fryns syndrome is an autosomal recessive multiple congenital anomaly/mental retardation syndrome characterized by coarse face, distal limb hypoplasia, and diaphragmatic anomalies. We describe a newborn girl with Fryns syndrome and Hirschsprung disease, an association that has been reported in five previous cases. These patients support the hypothesis that the neural crest plays a role in the pathogenesis of Fryns syndrome. Clinically asymptomatic or subtle anomalies that are in the spectrum of neural crest maldevelopment should be sought in all patients with Fryns syndrome including stillbirths, neonatal deaths, as well as long-term survivors. We suspect that the clinical observation about Hirschsprung disease and Fryns syndrome may provide insight into its molecular mechanisms and candidate genes.

Eye abnormalities in Fryns syndrome

Fryns syndrome is a rare, generally lethal, autosomal recessive multiple congenital anomaly (MCA) syndrome first described in 1979. Patients with the syndrome present with the classical findings of cloudy cornea, brain malformations, diaphragmatic defects, and distal limb deformities. Over 70 patients have been reported revealing a wide variety of phenotypic features. Although initially considered a major feature of Fryns syndrome, cloudy cornea has been relegated as a minor diagnostic sign and not commonly reported in patients since the original description. However, eye findings per se are not uncommon. Abnormal eye findings occasionally reported in Fryns syndrome potentially result in amblyopia and blindness, profoundly affecting neurologic outcome of those who survive the neonatal period. We reviewed 77 reported patients with Fryns syndrome and summarized the abnormal eye findings identified in 12 of the reported cases. In addition, we contribute three new patients with Fryns syndrome, one of which demonstrated unilateral microphthalmia and cloudy cornea.

A case of Fryns syndrome without diaphragmatic hernia and review of the literature

We report on a child with Fryns syndrome who showed a characteristic coarse hirsute facial appearance, bilateral cleft lip and palate, cardiac and renal anomalies, dilated bowel and distal limb abnormalities. However, diaphragmatic hernia, which is considered a cardinal feature in this condition, was absent in our patient. The parents were consanguineous supporting autosomal recessive inheritance.

Fryns syndrome: A review of the phenotype and diagnostic guidelines

Fryns syndrome (FS) is the commonest autosomal recessive syndrome associated with congenital diaphragmatic hernia (CDH) and comprises CDH, pulmonary hypoplasia, craniofacial anomalies, distal limb hypoplasia, and internal malformations. Although there have been more than 50 case reports on probands with FS, the diagnostic guidelines were formulated from a review of eight patients and modifications to the guidelines have only once been suggested. Recently, several case reports have described new anomalies in FS and other papers have highlighted the variation in expressivity found in FS. This paper examines the medical literature on FS to define the phenotype and to review the diagnostic guidelines. We conclude that CDH with brachytelephalangy and/or nail hypoplasia is strongly suggestive of the diagnosis and that pulmonary hypoplasia, craniofacial dysmorphism, orofacial clefting, and polyhydramnios are sufficiently frequent to be diagnostically useful. Other distinctive malformations that are consistent with FS include ventricular dilatation or hydrocephalus, agenesis of the corpus callosum, neuronal or cerebellar heterotopias, abnormalities of the aorta, renal cysts, dilatation of the ureters, bicornuate uterus, renal dysplasia, proximal thumbs, and broad clavicles.

Cleft-palate lateral synechia syndrome: insight into the phenotypic spectrum of Fryns syndrome?

BACKGROUND

In 1972, Fuhrmann et al. (Humangenetik 1972;14:196-203) described a novel syndrome consisting of cleft palate (CP) and lateral synechiae (LS) between the palate and the floor of the mouth. This constellation of malformations, since denoted as cleft-palate lateral synechiae syndrome (CPLS), is a rare syndrome; only five cases have been reported since the original description. Because of the paucity of recognized cases, little is known regarding the phenotypic spectrum of this presumably autosomal dominant condition.

CASES

We report two unrelated patients who presented with remarkably similar phenotypic features, including multiple intraoral synechiae (filiforme intraalveolar bands), cleft palate, micrognathia, and redundant lower lip tissue. Their phenotypic findings indicate a diagnosis of CPLS; however, case 3 (the monozygotic twin of case 2) had classic phenotypic features of Fryns syndrome.

CONCLUSIONS

This report presents two new cases of CPLS, and suggests that the CPLS phenotype may represent the mild end of the Fryns syndrome phenotypic spectrum. Supplementary material for this article can be found on the Birth Defects Research (Part A) website (http://www.interscience.wiley.com/ jpages/1542-0752/suppmat/67/fig5.xls).

Documentation of anomalies not previously described in Fryns syndrome

We report on a case of Fryns syndrome with microcephaly, multiple facial anomalies, hypoplasia of distal phalanges, diaphragmatic defect with a thin, translucent diaphragm, microphthalmia (right), anophthalmia (left), and multiple midline developmental defects including gastroschisis, central nervous system defects including left arrhinencephaly and cerebellar hypoplasia, midline cleft of the upper lip, alveolar ridge and maxillary bone, and cleft nose with bilateral choanal atresia. These defects add to our knowledge of the phenotype of Fryns syndrome.

Combination of diaphragmatic eventration and microphthalmia/anophthalmia is probably nonrandom

Two sporadic cases of eventration of the diaphragm are reported; one had bilateral colobomatous microphthalmia and the other had anophthalmia. Absence of polydactyly and presence of eventration rather than diaphragmatic hernia helped to exclude Fryns syndrome. These cases together with published cases with overlapping features support the thesis that this combination of defects is nonrandom and of heterogeneous cause. Some cases are due to a pleiotropic gene defect. In other cases, a polytypic developmental field involving an unknown developmental cascade common to the eye and diaphragm may provide a basis for the combination.